<!DOCTYPE HTML>
<html>
<head>
    <meta charset="UTF-8">
    <title>My WebSocket</title>
    <style>
        #message{
            margin-top:40px;
            border:1px solid gray;
            padding:20px;
        }
    </style>
</head>
<body>
    <label for="nickname">昵称: </label><input type="text" id="nickname" /><br/>
    <button onclick="conectWebSocket()">连接WebSocket</button>
    <button onclick="closeWebSocket()">断开连接</button>
    <hr/><br/>


    <label for="msg">频道号: </label><input type="text" id="toUser"/>
    <label for="msg">消息: </label><input type="text" id="msg"/>
    <button onclick="send()">发送消息</button>

    <div id="message"></div>
</body>
<script type="text/javascript">
    var websocket = null;

    //连接服务
    function conectWebSocket(){
        var nickname = document.getElementById("nickname").value;
        if(nickname == ""){
            alert("请输入昵称");
            return;
        }

        document.getElementById("nickname").setAttribute("readonly", "readonly");
        //判断当前浏览器是否支持WebSocket
        if ('WebSocket'in window) {
            websocket = new WebSocket("ws://localhost:8080/websocket2/" + nickname);
        } else {
            alert('Not support websocket')
        }

        //连接发生错误的回调方法
        websocket.onerror = function() {
            setMessageInnerHTML("error");
        };
        //连接成功建立的回调方法
        websocket.onopen = function(event) {
            setMessageInnerHTML("Loc MSG: 成功建立连接");
        }
        //接收到消息的回调方法
        websocket.onmessage = function(event) {
            setMessageInnerHTML(event.data);
        }
        //连接关闭的回调方法
        websocket.onclose = function() {
            setMessageInnerHTML("Loc MSG:关闭连接");
        }
        //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
        window.onbeforeunload = function() {
            websocket.close();
        }
    }
    //关闭连接
    function closeWebSocket() {
        document.getElementById("nickname").removeAttribute("readonly");
        websocket.close();
    }


    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //发送消息
    function send() {
        var message = document.getElementById('msg');
        //获取输入的文本信息进行发送
        var msg = message.value;
        var toUser = document.getElementById('toUser').value;
        var socketMsg = {msg:message.value,toUser:toUser};

        if (message.value == "") {
            alert("消息不能为空!")
        } else {
            if(toUser == ''){
                //群聊.
                socketMsg.type = 0;
            }else{
                //单聊.
                socketMsg.type = 1;
            }
            websocket.send(JSON.stringify(socketMsg));
            message.value = "";
        }
    }
</script>
</html>